Caster



Sheets-Sheet 1.

{NO ModeL) S. G. MENDENHALL.

GASTER.

Patented M131, 1885.

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(N0 ModL) 2 SheetsSheet 2. v S. G. MENDENHALL.

OASTER.

No. 314,964.- Patented Mar. 31, 1885.

F I G VHI W Y /m 1 UNiTED STATES PATENT OFFICE.

STEPHEN O. MENDENHALL, OF RICHMOND, INDIANA.

CASTER.

$FEGIFICATION forming part of Letters Patent No. 314,964, dated March 31, 1885.

Application filed November 15, 1884.

To aZZ whom it may concern.-

Be it known that I, STEPHEN O. MENDEN- HALL, a citizen of the United States, residing at Richmond, in the county of Wayne and State of Indiana, (present business address Cincinnati, Ohio,) have invented certain new and useful Improvements in Casters, of which the following is a specification.

The present invention relates to improvements in both single and double floor-wheel casters. It consists, first, in a form of top adapted to provide lateral anti-friction bearing both at top and bottom of the spindle, whether said spindle be attached to the axle or truck of atwo floor-wheel caster or to the saddle 1 of a single floor-wheel caster, providing that in each case the truck, axle, or saddle has supported thereon a vertical anti-friction wheel adapted to find bearing 011 the under side of the furniture-plate. It consists, second, in an improved device for adapting such a single vertical friction-wheel to a single floor-wheel caster, as will be hereinafter more fully described.

In order that my invention may be more fully understood, I will proceed to describe it with reference to the accompanying drawings, in which- Figure I is a side elevation of a two floor- Wheel caster embodying my improvements. Fig. II is a front elevation thereof. Fig. III is a vertical section of the same. Fig. IV is a similar view of the same improvements as applied to non-separating casters. Fig. V is a side elevation showing the improvements applied to a single floor-wheel caster. Fig. VI is a vertical sectional view showing a simple top adapted to the improved form of single floor-wheel casters. Fig. VII is a detail View of the trunnion-pin for supporting the vertical anti-friction wheel. Fig. VIII is a a horizontal sectional view of chambered antifriction top. Fig. IX is a similar viewshowing the same on a larger scale in order to represent more clearly the means whereby the rollers are held-in position. Fig. X is a diagrammatic view showing the use of three antifriction rollers.

1 1 are the floor-wheels, 2 the spindle, and 3 the axle, of my improved caster. These (No model.)

able form. XVhen applied to atwofloor-wheel caster, the spindle 2 is preferably made to oscillate in the axle-cavity, as shown in Fig. III, so as to allow of relative vertical motion between the aXle and top on an uneven floor without binding on the spindle or top. Said top is preferably formed in halves 4 5, fixed together by rivet 6 and by cap-plate 7 in a manner described in a copending application. By forming the top in halves I am enabled to cast a screw-thread, 8, on the exterior of the top, to adapt the same to be more readily attached to the furniture. To assist in such attachment I form the exterior of the enlarged chambered portion 9 of the top of hexagonal or other regular polygonal form, the outer cap, 7, being made of corresponding shape, so as to closely embrace the same. This con struction enables the use of a wrench for forcing the top into the furniture-leg or other part. At top the spindle 2 (see Figs. III and IV) is provided with a stud, 10, occupying a central hole in the washer or diaphragm 11, which is firmly fixed in the top when the two parts thereof are fastened together. By casting the upper end of the spindle in a chill, and forming the diaphragm 11 of chilled steel, both these parts are made exceedingly hard and smooth, so as to render them subject to little, if any, wear in the ordinary use of the caster. It will be seen that this stud and washer provide practically anti-friction bearing laterally for the top of the spindle. At the point where the spindle would bear against the bottom of the furniture socket or top I enlarge said top, as already described, and place therein a se ries of loose anti-friction rollers, 12, which are preferably made of a diameter equal to that of the spindle, as shown in Fig. VIII. In order to avoid the possibility of an uneven bearing due to irregularities in the casting or the fitting together of the two parts of the top, I may employ a ring, 13, of smooth metal,-placed within the top, for affording lateral bearing for the peripheries of said rollers 12.

Reference is made to Fig. IX for an illustration of the relation of the spindle and rollers when assembled. The bearing-faces of the rollers are made flat and parallel, so as to pre- 50 parts may be of the represented or other suitvent one rising over the other. It will be emcee seen by the dotted circles in Fig. IX that the I VI.

circle passing through the centers of said rollers lies considerably without the circle passing through the points of contact between the rollers. This being the case, and the rollers being placed in the chamber of the top in such manner as to nearly fill the same, the said rollers are prevented from falling out in case of the withdrawal of the spindle. It is thus seen that the use of rollers of the proper size and shape within a chambersufficiently contracted is possible in a separating as well as in a non separating caster, providing said rollers be placed in the chamber in suificient number. If, for example, rollers of the same size as those shown in Fig. IX be arranged, as shown in Fig. X, but three in the chamber, the withdrawal of the spindle will leave no impediment whatever to the falling out andlosing of the rollers, and the same would be the case with four or five rollers, providing the proportion between the spindle, rollers, and chamber be maintained the same. In order to maintain the parts together in the most perfect working form,-the spindle must be held concentrically between the chamber, and the antifriction rollers must nearly or quite fill the annular space remaining, and must be of such size and form that they cannot by being slightly compressed be sprung out of place, and cannot ride one over the other. It will be seen that if large balls of this same diameter be employed the caster will be rendered too bulky, while if small balls be employed it will be impossible to retain. them in the circle by reason of the fact that the circles of their centers and of their contact-points would be practically coincident, and their form would render them liable to ride one over the other. If, on the other hand, the three horizontal antifriction rolls shown in the diagram Fig. X be mounted on fixed axial bearings or journals, the caster possesses equal disadvantages. In the first place, friction on the journal is considerable as compared with that of a rolling bearing, and the consequent wear soon loosens the bearing between spindle and rollers. The consequence is, the rollers being already so far apart, the spindle is apt to fall down between them, greatly increasing the friction and strain, and causing the spindle in its rotation to have a jumping, irregular motion.

The rollers 12 may be out off of tubing, so as to be hollow, as shown. They may be made very cheaply in this manner, and are very light and strong; but I do not wish to be understood'as limiting myself to such a mode of producing said rollers, as they may be formed by stamping or in any other desired manner.

In combination with the top and bottom lateral anti-friction devices of the caster I employ a vertical anti-friction roller, 14, mounted on the aXle-casting, as shown in Figs. I to IV, or upon the saddle and spindle when the same are formed together for a sin gle floor-wheel caster, as shown in Figs. V and The latter form is peculiarly adapted for the construction of asimple one floor-wheel. anti-friction caster.

A boss or arm, 15, is cast upon. the spindle 2, projecting over the floor wheel or roller. Said spindle and boss are then bored through horizontally, as shown in Fig. VI in dotted lines, for iheinsertion of a wrought pin, 16, whose shoulder 17 engages with the face of the boss 15, so as to prevent binding of the antifriction roller between the head 18 of the pin and the said boss, said roller being arranged to revolve upon said shouldered portion of the pin. Then in position, with the anti-friction roller journaled thereon, the pin is riveted over and thus fixed to the spindle. A single floor-wheel spindle of this construction is applicable as well to the anti-friction top shown in Fig. V as to a simple top shown in Fig. VI, in which form of caster vertical anti-friction alone is provided for.

I am aware that it has before been pro posed to form a socket-top for casters in two parts, and to provide such a top with screwthreads, adapting it to be forced into the furniture by means of a nut on the lower end of the top.

Having thus described my invention, the following is what I claim as new therein and desire to secure by Letters Patent:

1. A stemcaster socket -top cast in two parts, each part having one half of a screwthread, which halves register when the two parts are put together, and one-half of an enlarged chamber at bottom having a polygonal contour, in combination with a polygonal cap forced over said chambered portion, for the purpose set forth.

2. In combination with a furniture sockettop having an enlargement or chamber at bot torn, horizontal anti-friction rollers occupying said chamber, a spindle occupying said socket and bearing laterally on said rollers, and a single vertical anti-friction roller bearing against the bottom of said chamber, substan tially as set forth.

3. The combination of a vertical socket having horizontal washer or diaphragm at top and horizontal enlargement or chamber at bottom, loose horizontal anti-friction rollers within said chamber, a spindle bearing on said rollers laterally, and having a stud at top occupying a hole in said washer or diaphragm,

and a Vertical anti-friction wheel or roller mounted upon the wheel truck or spindle and bearing on the bottom of said chamber, substantially as set forth.

4. In combination with a furniture top or socket having a horizontal enlargement or chamber, a spindle arranged concentrically within said chamber, and loose horizontal anti-friction rollers having flat bearing-faces adapted to fill the annular space between the spindle and wall of the chamber and prevent the falling out of said rollers when said spindle is removed, substantially as set forth.

5. In combination with a spindle having a rod horizontal boss or arm thereon, a vertical 1 pin, and a furniture plate or attachment rest' anti-friction wheel or roller supportedon said ing upon said anti-friction roller, substanboss, substantially as and for the purpose set tially as set forth.

forth. '7. In a caster, loose hollow anti-friction 5 6. In combination with a single floor wheel rollers, arranged substantially as described.

or roller and its axle a saddle and spindle supported on said axle, a horizontal boss cast STEPHEN MENUENHALL' on said spindle, a shouldered wrought pin \Vitnesses:

OOTAVIUS KNIGHT, HARRY E. KNIGHT.

occupying a horizontal bore in said boss, a IO vertical anti-friction roller supported on said 

